Two wrongs don't make a right
If somebody insults you or harms you, doing the same to them will not solve the problem. It will most likely cause a back-and-forth conflict without an end. If somebody is mean to you, don’t be mean to them in return.
After looking through a number of pages of this branch I found the post above. If you are not "mean to them", they continue to be mean to you and become meaner and meaner. What is the way out? Is there a saying indicating to people what they should do under the circumstances?